Book excerpt: From master teacher George J. Klein, MD, this stepwise book is for those with a working knowledge of electrophysiology who have looked at a complicated ECG or intracardiac tracing and drawn a blank, not recognizing a pattern from their personal experience, and without a good idea of how to proceed or venturing a guess with variable confidence. Dr. Klein presents strategies that he has found useful, not just by providing an “answer,” but also exploring how he solved the problem with a systematic approach using “tools” of analysis that applies to both ECGs and EGM tracings.